Chemical heating pad and method of manufacture



y 8, 1940. F. L. REYNOLDS ET AL 2,202,067

CHEMICAL HEATING PAD AND: IETHOD 01 MANUFACTURE Filed ,Ilay 27, 1938 IN V EN TORS L BERT BY JACK H. 5/5

ATTORNEY Patented May 28, 1940 UNITED STATES CHEMICAL HEATING PAD AND METHOD OF MANUFACTURE Frederick L. Reynolds, Mill Valley, and Leon Markel and Jack A. Siebert, San Francisco,

Calif., assignors,

by mesne assignments, to

United States Appliance Corporation, San Francisco, Calif., a corporation of California Application May 27, 1938, Serial N0. 210,436

6 Claims.

This invention relates to chemical heating pads and methods for their manufacture. More particularly it is concerned with the construction and manufacture of devices making use of an exothermic chemical reaction, for the generation of heat.

- Small chemical heating devices, intended to be used to generate a predetermined amount of heat, and then to be discarded, have come into wide commercial use, particularly for the purpose of permanently waving hair. As disclosed in Reynolds Patent No. 2,153,677, entitled Chemical heating pad for permanent hair waving, one type of device for this purpose makes use of an 1 inner flexible assembly, consisting of sheets of absorbent paper in contact with one or more sheets of aluminum foil. This assembly is saturated with a chemical solution capable of exothermic reaction with aluminum foil, and is 20. enclosed within a protecting wrapper, when applied to the wound hair. Several factors contribute to the practical success of such a pad. Among other factors the inner assembly should be constructed in such a manner that it can be readily saturated by solution, and so that when saturated the solution is brought into intimate contact with all surfaces of aluminum foil. In the assembly disclosed in said co-pending Patent No. 2,153,677, the paper is made of asbestos, and the assembly consisting of two sheets of asbestos paper with an interposed sheet of aluminum foil, is perforated and then stitched along the side edges to retain the sheets together.

The present invention has for its primary object the production of an improved assembly for a chemical heating pad of the above character. More particularly the present invention is characterized by the absence of stitching to retain the assembly together, and by an arrangement of perforations which interlock the sheets together in intimate surface-to-surface contact.

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

Fig. 1 is a plan view showing apparatus for carrying out the desired perforating operation.

Fig. 2 is a cross-sectional view taken along the line 2-2 of Fig. 1.

Fig. 3 is an enlarged cross-sectional detail, illustrating what takes place during the perforating operation.

Fig. 4 is an enlarged plan detail of an assembly with perforations such as applied by the machine of Figs. 1 to 3 inclusive.

Fig. 5 is a cross-sectional detail along the line 5-5 of Fig. 4, and on the same scale as Fig. 4.

Our assembly can best be understood by first I describing a suitable perforating appliance used in its manufacture. Referring to Figs. 1 and 2, the appliance illustrated consists of a pair of rolls l0 and II, which are carried by the machine frame l2. Roll I0 is carried by shaft I 3, the ends 10 of which are journalled to the frame l2. Gear II is representative of suitable drive means. Roll H is carried by a shaft l6, which likewise has its ends joumalled to the frame l2, preferably with journal blocks l5 capable of adjustment relative 15 to the shaft I 3. Strips of materials to be passed between the rollers I0 and Il are received by the guideway H, the bottom wall it of which is spaced with respect to an upper guide plate l9. Guide plate l9 has a curved end portion 2|, to 20 direct the strips of material between the rolls l0 and II.

The periphery of the roll I0 is provided with spaced rows of perforating teeth 22a and 22b (Fig. 3). In a typical instance the pitch be- 25 tween adjacent teeth 22a or 22b, can be in the neighborhood of of an inch, and the teeth 22b are oifset a distance equal to one-half this pitch, as shown in Fig. 3. Each tooth is formed V- shaped as shown in Fig. 3, from a sheet metal 30 stock of suitable thickness, as for example sheet metal about of an inch thick. Adjacent rows or series of teeth are spaced apart as shown in Fig. 1, and are in register with circumferential grooves 23, formed in the periphery of roll Ii. 35

As illustrated in Fig. 3, the machine is preferably adjusted so that normally the ends of teeth 22a and 22b extend slightly within the grooves 23. The grooves are slightly wider than the thickness of the teeth, and in a typical instance may be 40 about of an inch wide where the teeth are about of an inch thick.

The perforating appliance also includes suitable means for removing perforated sheets from the roll I0, and for carrying away the completed 45 assembly to suitable cutting and possibly folding means. Thus carried by a, bar 24, extending below the roll l0, there is a stripper 26, which is provided with a plurality of fingers 21, extending between the rows of teeth 22a. and 22b. The perforated assembly passes beneath stripper 26, through space 28, for delivery along the guideway 29.

In some instances it is desirable to automatically introduce a wrapper into the machine for BI than the speed of rotation of the perforating sheets 22a and 22b. A wrapper 31 is shown being introduced over roll it, and beneath the perforated assembly 34.

To form our novel assembly by use of the above appliance, sheets of absorbent material, like asbestos paper, are employed together with sheets of aluminum foil. Strips of such material are -supplied to the perforating machine shown in Figs. 1 and 2. In Fig. 2 these strips have been designated by numerals l and 2, numerals i referring to three strips of asbestos paper, and numerals 2 referring to two strips of aluminum foil interposed between the strips of paper. In passing between the rolls l0 and Ii, these strips are continuously perforated substantially in the manner illustrated in Figs. 4 and 5. In pressing through the several sheets of material the points 220 and 22b form two sets of perforations Ia and 3b, which are staggered, as illustrated in Fig. 4. Note that these perforations, or rather indentations, are in the form of V-shaped cavities in the assembly, and that they penetrate through all of the sheets of aluminum foil. In plan the perforations are substantially rectangular shaped.

The last sheet I of asbestos paper is more or less penetrated by the points, although not to the extent of forming a clean opening. The edges of the aluminum foil adjacent the perforations are bent into the adjacent sheet of asbestos paper to form a mechanical interlock or retention.

The net effect of the above procedure is to lock the assembly together whereby it can be cut, bent and handled in usage, without causing any substantial separation between the sheets. Thus it is unnecessary to carry out any stitching as disclosed in said co-pending Patent No. 2,153,677, and the assembly is a complete unit of itself, requiring only a proper chemical solution, to carry out a heating operation.

The chemical solution employed with an assembly as described above, will vary in different instances, depending upon requirements. As pointed out in said co-pending Patent No. 2,153,677 one solution which can be employed is as follows:

Ammonium chloride b Sufficient water to make cc. of solution The weight of the absorbent paper employed, and the gauge of the aluminum foil, can vary in accordance with requirements. Good results have been secured by using an aluminum foil having a gauge of about 0.0015 inch, and with 6 pound asbestos paper. An assembly made as described herein can be used to make a complete pad of the type disclosed in said co-pending Patent No. 2,153,677, or it may be folded and enclosed within a wrapper in the manner disclosed and claimed in co-pending Reynolds and Markel Patent No. 2,133,115. In any event the adjacent surfaces of the aluminum foil and asbestos paper are maintained in intimate contact, whereby all surfaces of the aluminum foil are contacted with chemical solution, when the solution is applied to the assembly. Application of a definite amount of solution to one side of the assembly is followed immediately by saturation of the entire assembly. due to penetration of solution through the perforations.

We claim:

1. In a chemical heating pad of the character described, an assembly comprising at least two sheets of absorbent paper and one interposed sheet of aluminum foil, said sheets being interlocked together as a unitary assembly by perforations extending over the entire area of the same.

2. In chemical heating pads of the character described, two sheets of absorbent asbestos paper and an interposed sheet of aluminum foil, perforations distributed over the entire area of said sheets, said perforations extending through the aluminum foil, the turned edges of the foil adjacent said perforations serving to interlock all of said ,sheets together to form a compact assembly.

3. In a chemical heating pad of the character described, a pair of sheets of absorbent paper and a sheet of aluminum interposed between said paper sheets, said sheets being provided with substantially rectangular shaped perforations extending over the entire area of the same, turned edges of the aluminum foil adjacent said perforations serving to mechanically lock all of said 0 sheets together to form a unitary assembly.

4. In a chemical heating pad of the character described, a pair of sheets of absorbent paper and a sheet of aluminum interposed between said paper sheets, said sheets being provided with substantially rectangular shaped perforations extending over the entire area of the same, turned edges of the aluminum foil adjacent said perforations serving to mechanically look all of said sheets together to form a unitary assembly, said perforations being in staggered rows.

5. In a chemical heating pad of the character described, a plurality of sheets of asbestos paper and sheets of aluminum foil interposed between the sheets of asbestos paper, all of said sheets being made into a compact assembly in which the sheets have intimate surface to surface contact, said assembly being retained together by turned edges of the aluminum foil adjacent perforations distributed over the entire area of the assembly.

6. In a chemical heating pad of the character described, a plurality of sheets of asbestos paper LEON MARKEL. JACK A. SIEBERT. 

